The present invention relates to a device for supporting a recording disk, and particularly to a disk holding device for supporting a disk as a recording medium, such as an optical disk device and a magneto-optical disk device.
There is a known disk as a recording medium of information signals, such as an optical disk and a magneto-optical disk. In a disk driving device, which information signals are recorded on and reproduced from a disk, the disk is positioned by a turntable fixed to a motor rotating shaft of a driving motor.
FIG. 6 is a sectional view showing a disk holding device of a known disk driving device. In FIG. 6, indicated by reference numeral 1 designates a driving motor, by 2 a motor rotating shaft, by 3 a motor fixing mount, by 4 a turntable, by 5 a disk, by 6 a disk clamping body, by 7 a pressing arm, by 8 a tension spring, by 9 an upper bearing, by 10 a lower bearing, by 11 a motor coil, and by 12 a thrust bearing.
The motor rotating shaft 2 is rotatably supported by the upper bearing 9 and the lower bearing 10, and is wound with the motor coil 11. The turntable 4 is fixed to the motor rotating shaft 2 so that they are formed in one unit, which is supported by the motor fixing mount 3. The disk 5 is clamped by the disk clamping body 6 pressed so as to be brought into press contact with the turntable 4 and the pressing arm 7 for pressing the disk clamping body 6 from above by the tension spring 8.
Pressing force F"ugr" applied by the pressing arm 7 is supported by the thrust bearing 12 through the motor rotating shaft 2. When the driving motor 1 is driven, the motor rotating shaft 2 is rotated under the state that it is supported by the upper bearing 9, the lower bearing 10, and the thrust bearing 12.
However, since a known disk holding device is constructed as described above, in the case where a clearance exists between the motor rotating shaft 2 and the upper bearing 9 or the lower bearing 10, there has been a problem that when the driving motor is rotating, as shown by a locus A in FIG. 7, end play (shaft backlash) becoming so-called precession occurs, so that recording and reproducing capacity of the disk driving device is lowered.
Thus, the invention provides a disk holding device in which even in the case where there is a clearance between a motor rotating shaft and an upper bearing or a lower bearing of a driving motor, it is possible to suppress the occurrence of end play (shaft backlash) becoming so-called precession when the driving motor is rotating.
In a disk holding device of the invention, a protruding portion of a disk clamping member disposed in the same axial direction as a motor rotating shaft, which is rotatably supported by an upper bearing and a lower bearing and protrudes upward from a driving motor, is pressed in an axial direction of the motor rotating shaft and in a direction perpendicular to the motor rotating shaft by an inclined portion of a pressing member having a predetermined inclination angle with respect to an axis of the motor rotating shaft. By this, even in the case where there is a clearance between the motor rotating shaft and the upper bearing or the lower bearing, it is possible to suppress the occurrence of end play (shaft backlash) becoming so-called precession when the driving motor is rotating.
Moreover, the pressing member includes the inclined portion with an inclination angle of 95xc2x0 to 104xc2x0 with respect to the axis of the motor rotating shaft. By this, even in the case where there is a clearance between the motor rotating shaft and the upper bearing or the lower bearing, it is possible to suppress the occurrence of end play (shaft backlash) becoming so-called precession when the driving motor is rotating.
Moreover, the disk clamping member includes the spherical protruding portion pressed by the inclined portion of the pressing member. By this, even in the case where there is a clearance between the motor rotating shaft and the upper bearing or the lower bearing, it is possible to suppress the occurrence of end play (shaft backlash) becoming so-called precession when the driving motor is rotating.
Moreover, the clamping member includes the cylindrical protruding portion pressed by the inclined portion of the pressing member. By this, even in the case where there is a clearance between the motor rotating shaft and the upper bearing or the lower bearing, it is possible to suppress the occurrence of end play (shaft backlash) becoming so-called precession when the driving motor is rotating. Further, as compared with the case where the spherical protruding portion is brought into surface contact with the inclined portion of the pressing member, rotation load due to contact can be reduced by making line contact with the cylindrical protruding portion.
Moreover, the disk clamping member includes the conical protruding portion pressed by the inclined portion of the pressing member. By this, even in the case where there is a clearance between the motor rotating shaft and the upper bearing or the lower bearing, it is possible to suppress the occurrence of end play (shaft backlash) becoming so-called precession when the driving motor is rotating. Further, as compared with the case where the spherical protruding portion is brought into surface contact with the inclined portion of the pressing member, rotation load due to contact can be reduced by point contact with the conical protruding portion.
Moreover, in a disk holding device of the invention, a protruding portion of a disk clamping member provided in the same axial direction as a motor rotating shaft, which protrudes upward from a driving motor, is pressed in an axial direction of the motor rotating shaft and in a direction perpendicular to the motor rotating shaft by an inclined portion of a pressing member having a predetermined inclination angle with respect to an axis of the motor rotating shaft. By this, when the driving motor is rotating, it is possible to suppress the occurrence of end play (shaft backlash) becoming so-called precession in the motor rotating shaft.